Variable speed gearing, particularly for motor vehicles



March 15, 1932. VALLETTA VARIABLE SPEED GEARING, PARTICULARLY FOR MOTOR VEHICLES Original Filed Nov. 19, 1929 Patented Mar. 15, 1932 UNITED STATES PATENT oF CE VITTORIQ VALLETTA, or TUnImrrALY, assrenon T0 FIAT SOCIETA ANONIMAJQT roam, ITALY H VARIABLE SPEED GEARING, PARTIGULARLY FOR MOTOR VEHICLES Original application filed November 19, 1929, Serial No. 408,293, and in Italy December 12, 1928. Divided and this application filed September 18, 1930. Serial No. 482,840.

This invention refers to a change speed gearing and has for its object improvements in my invention described in the United States Patent No. 1,794,264 granted February 24, 1931, of which this application is a division.

The variable speed gearing is similar in general construction to that described in said specification, i. e. the next lower speed to the direct drive (or third gear) is obtained through the medium of two eccentric gear sets 1 with internal and external sets of teeth, respectively, while the lower speeds are obtained by means of axially slidable gear sets. The usual pinions connecting the engineshaft with the countershaft are driven by the engine shaft under speed reduction through the two eccentric gear sets for the third speed, and in the total transmission ratio from the engine shaft to the countershaft this reduction is added to that effected by the pair of pinions actuating the countershaft.

The purpose of the present invention is essentially to simplify construction and to v ncrease at the same time the strength of the gearing while facilitating the operation of dismounting its parts.

A further object of this invention is to provide a variable speed gearing, wherein the gearing members are supported by bush bearings, means being provided for greasing said bush bearings through a forced circulation of an oil lubricant.

A still further. object of theinvention is o provide a variable speed gearing, wherein the movable gear set for the first and second speeds slides by means of teeth on the sleeve controlling the third and fourth speeds, which sleeve is slidably keyed in turn on an extension of the transmission shaft.

The accompanying drawings show, by way of example, a construction of the variable speed gearing according to the invention.

Fig. 1 is a vertical longitudinal section hrough the gearing which is shown in two parts for convenience.

Fig. 2 is a partial cross section showing the oil pump.

The gearbox is divided vertically into two parts 1 and 1a connected together in any suitable manner permitting rapid and easy dismounting of the various-gearing members. On the engine shaft 2 are teeth 6 meshing with the internal set of teeth 7 of the C-section ring which is made in two parts 8a: 86 'joined by screws 80. The part 8a carries the internal set of teeth 7 and the part 8?) is provided with teeth 9 meshing with the internal set of teeth 10 of the crown 11 having the hub 12.

The pinions. 7 and 9 of the ring 8a: 8b are eccentrically disposed with respect to the axis of the engine shaft 2and are supported by a suport 14 also eccentric to the said axis and held in a corresponding recess in the gearbox- In the support 14 is fitted a sleeve 16 withan eccentric extension supporting a ball bearing 17 for the engine shaft 2. The support 14 reaches into the annular hollow of the C-section ring 8az8b and supports the ring through two roller bearings 15a and 15?), this latter being exactly in the middle plane of the pinions 6:7 and 9:10 of which it absorbs the reaction; The shaft 2 carries within the hub 12 a large bearing preferably divided into two parts 13a and 13?), on which the hub 12 turns with-the integral pinion 4 and set of external teeth 12a. The pinion 4 meshes with the corresponding pinion 5 keyed on the countershaft 3. r

The engine shaft 2 reaches within the bell 20 of the transmission shaft 22. Between the corresponding ends of the shaft 2 and bell 20 are interposed bush bearings 23a and 24; The ball bearing 26 fast with the box 1a serves for supporting the transmission shaft 22. The bell-shaped end 20 of the shaft 22 has external feathers or teeth 20a meshing with a corresponding internal set of teeth 19a cut in the longitudinally slidable sleeve 19. This latter is provided at one end with an internal set of teeth 19?) adapted to mesh eitherwith theteeth 12a (for the third speed) or with teeth 18a on a sleeve fast with the'engine shaft 2 (for direct drive). A fork engages the recess 21 at one end of the sleeve 19 for effecting longitudinal displacement of the sleeve.

The sleeve 19 has outer feathers or teeth 'the pinions 29 and 27 meshing with'the pinions 30 and 28, respectively. In this construction the gears .4 and 5 are spur 'wheels and the countershaft 3 is supported by the two ball bearings 32 and 33 without any thrust bearing. v H

The countershaft 3 extends beyond the ball bearing 33 and forms. the rotating hub 3a of a vane pump for oil circulation. Said hub 3a has a cross slit in which two vanes 41 are movable and serve to compress the oil in an'eccentric chamber 42 formed in a body 49 attached to the end of the casing 1. An oil inlet 43 and an oil outlet 44 are provided in the walls of the chamber 42.- Before reaching the pump, the oil is caused to fiow through a filter 45 preferably consisting of a perforated sleeve 46 surrounded by a wire gauze, the outer end of which is screw-threaded and provided with a nut 47 for'screwing it on the lower end of the box 1a.

The oil flowing under pressure" from the vane pump circulates through openings or channels Fformed in the various stationary and rotating members, thereby ensuring a continuous flow of oil to the essential parts, such as the bearings and the gears. The oil flows through'the aforesaid openings into the engine shaft 2, then through holes'to the bush bearings and to the third speed gears, then through ports in the member 14 toa cross conduit F in the casing wall from g which it fallsv on the bottom of'the gearbox 1a where it cools before the pump. a

The various members mounted on the engine shaft are held against shoulders on the shaft by means of clamp rings 25, and covers 35 and 36 protect the lower portionjof the gearbox 1a and the bearing 17, respectively. The cover 35 carries the case 35a for the Worm gear 37: 38 operating the speedometer. I The sleeve 39 mounted on the transmission shaft 22 is'divided in two parts and besides being returned to carrying the wheel 37 is provided with a' flange39a for coupling with the transmiss'ion of the vehicle.

l Vhat I claim is:

1. In a variable speed gearing, in combination; a gearbox, a driving shaft, said shaft having an axial bore, a pinion on said shaft entering said gearbox, a driven shaft co-- axially arranged to said driving shaft and having one hell shaped end, cylindrical bear ings in said bell supporting said driving shaft, a C-shaped ring with external and internal teeth fitted in said gearbox eccentrically to the driving shaft and meshing inter nally with the pinion on the driving shaft,

'of said driving shaft.

2.; In. a change-speed mechanism,in combination; a gearbox, a driving shafthaving an axial bore and entering said gearbox, a driven shaft co-axial to said driving shaft and having one of its ends in the shape of a bell, cylindricalbearings in said bell support-ing said'driving shaft, a C-shaped ring with external and internal teeth fitted in said gearbox eccentrically to said driving shaft and meshing internally with a pinion on the driving shaft, a sleeve supported by said driving shaft by means of a cylindrical bearing and having an inner set of teeth meshing with the external teeth of said C-shaped ring, a secondary shaft, ary shaft to said sleeve, a vane pump fitted in the gearbox wall and operated by said secondary shaft to drawin the lubricating oil from the bottom of said gearbox and force it into 'said cylindrical bearings through the axial bore and radial holesof said driving shaft. i In testimony that I claim the foregoing as my invention, I have signed my name.

I VITTOR-IO VALLETTA.

ears connecting said second 

